Defining an additivity framework for mixture research in inducible whole-cell biosensors

A novel additivity framework for mixture effect modelling in the context of whole cell inducible biosensors has been mathematically developed and implemented in R. The proposed method is a multivariate extension of the effective dose (EDp) concept. Specifically, the extension accounts for differential maximal effects among analytes and response inhibition beyond the máximum permissive concentrations. This allows a multivariate extension of Loewe additivity, enabling direct application in a biphasic dose-response framework. The proposed additivity definition was validated, and its applicability illustrated by studying the response of the cyanobacterial biosensor Synechococcus elongatus PCC 7942 pBG2120 to binary mixtures of Zn, Cu, Cd, Ag, Co and Hg. The novel method allowed by the first time to model complete dose-response profiles of an inducible whole cell biosensor to mixtures. In addition, the approach also allowed identification and quantification of departures from additivity (interactions) among analytes. The biosensor was found to respond in a near additive way to heavy metal mixtures except when Hg, Co and Ag were present, in which case strong interactions occurred. The method is a useful contribution for the whole cell biosensors discipline and related areas allowing to perform appropriate assessment of mixture effects in non-monotonic dose-response frameworksThis research was supported by MINECO grants CGL2010-15675 and CTM2013-45775-C2-2-R

Nanoparticle size influences the proliferative responses of lymphocyte subpopulations

International audience12 nm gold nanoparticles induce cell mediated responses accompanied by inflammatory natural killer cell stimulation, whereas 2 nm gold nanoparticles are more efficiently uptaken without inducing dendritic cell maturation or lymphocyte proliferation

Basophil Activation Test Utility as a Diagnostic Tool in LTP Allergy

Plant-food allergy is an increasing problem, with nonspecific lipid transfer proteins (nsLTPs) triggering mild/severe reactions. Pru p 3 is the major sensitizer in LTP food allergy (FA). However, in vivo and in vitro diagnosis is hampered by the need for differentiating between asymptomatic sensitization and allergy with clinical relevance. The basophil activation test (BAT) is an ex vivo method able to identify specific IgE related to the allergic response. Thus, we aimed to establish the value of BAT in a precise diagnosis of LTP-allergic patients. Ninety-two individuals with peach allergy sensitized to LTP, Pru p 3, were finally included, and 40.2% of them had symptoms to peanut (n = 37). In addition, 16 healthy subjects were recruited. BAT was performed with Pru p 3 and Ara h 9 (peanut LTP) at seven ten-fold concentrations, and was evaluated by flow cytometry, measuring the percentage of CD63 (%CD63+) and CD203c (%CD203chigh) cells, basophil allergen threshold sensitivity (CD-Sens), and area under the dose–response curve (AUC). Significant changes in BAT parameters (%CD63+ and %CD203chigh) were found between the controls and patients. However, comparisons for %CD63+, %CD203chigh, AUC, and CD-Sens showed similar levels among patients with different symptoms. An optimal cut-off was established from ROC curves, showing a significant positive percentage of BAT in patients compared to controls and great values of sensitivity (>87.5%) and specificity (>85%). In addition, BAT showed differences in LTP-allergic patients tolerant to peanut using its corresponding LTP, Ara h 9. BAT can be used as a potential diagnostic tool for identifying LTP allergy and for differentiating peanut tolerance, although neither reactivity nor sensitivity can distinguish the severity of the clinical symptoms.Partial funding for open access charge: Universidad de Málaga. This research was funded by grants from the “Instituto de Salud Carlos III” (ISCIII) of the Ministry of Economy and Competitiveness: PI17/01318, PI18/00288, PI21/00346, AC18/00031; RETICS ARADyAL (RD16/0006/0001, RD16/0006/0007); Sara Borrell (CD20/00085) Program; RICORS (RD21/0002/0008, RD21/0002/0058); and Next Generation EU funds. Andalusian Regional Ministry of Health (PE-0039-2018, RH-0085-2020, and PI-0099-2020), Senior Clinical Researcher Program (B-0005-2019), and Nicolas Monardes Program (RC-0004-2021). Roche Pharma S.A. “Stop Fuga de Cerebros” Program (SFC-0002-2020). Grants were co-funded by the European Regional Development Fund (ERDF). “Una manera de hacer Europa” “Andalucía se mueve con Europa”

Construction of a self-luminescent cyanobacterial bioreporter that detects a broad range of bioavailable heavy metals in aquatic environments

Frontiers in Microbiology 6 (2015): 186 This Document is Protected by copyright and was first published by Frontiers. All rights reserved. It is reproduced with permissionA self-luminescent bioreporter strain of the unicellular cyanobacterium Synechococcus sp. PCC 7942 was constructed by fusing the promoter region of the smt locus (encoding the transcriptional repressor SmtB and the metallothionein SmtA) to luxCDABE from Photorhabdus luminescens; the sensor smtB gene controlling the expression of smtA was cloned in the same vector. The bioreporter performance was tested with a range of heavy metals and was shown to respond linearly to divalent Zn, Cd, Cu, Co, Hg, and monovalent Ag. Chemical modeling was used to link bioreporter response with metal speciation and bioavailability. Limits of Detection (LODs), Maximum Permissive Concentrations (MPCs) and dynamic ranges for each metal were calculated in terms of free ion concentrations. The ranges of detection varied from 11 to 72 pM for Hg2+ (the ion to which the bioreporter was most sensitive) to 1.54-5.35 μM for Cd2+ with an order of decreasing sensitivity as follows: Hg2+ >> Cu2+ >> Ag+ > Co2+ = Zn2+ > Cd2+. However, the maximum induction factor reached 75-fold in the case of Zn2+ and 56-fold in the case of Cd2+, implying that Zn2+ is the preferred metal in vivo for the SmtB sensor, followed by Cd2+, Ag+ and Cu2+ (around 45-50-fold induction), Hg2+ (30-fold) and finally Co2+ (20-fold). The bioreporter performance was tested in real environmental samples with different water matrix complexity artificially contaminated with increasing concentrations of Zn, Cd, Ag, and Cu, confirming its validity as a sensor of free heavy metal cations bioavailability in aquatic environmentsThis study was funded by MINECO grants CGL2010-15675 and CTM2013-45775-C2-2-

Co, Zn and Ag-MOFs evaluation as biocidal materials towards photosynthetic organisms

In the present study, the biocidal activity of three different metal organic frameworks (MOFs) based on Co (Co-SIM1), Zn (Zn-SIM1) and Ag (Ag-TAZ) has been evaluated towards one green alga and two cyanobacteria. These organisms are present in fresh- and seawater and take part in the early stages of the biofouling process. The biocidal activity of these materials was evaluated by measuring chlorophyll a concentration and by inhibition zone testing. After 24 h of exposure the three different MOFs caused > 50% of chlorophyll a concentration inhibition towards both cyanobacteria, however, although the green alga presented a great sensitivity for Ag-TAZ (reaching 90% of chlorophyll a concentration inhibition), it was much more resistant to the rest of MOFs. Bioavailability of these metals was studied using ICP-MS, the chemical speciation program Visual MINTEQ, and a heavy metal bioreporter bioanalytical tool. We have elucidated that the biocidal activity presented by these MOFs was due to the dissolved metals released from them and more exactly, it depended on the bioavailability presented by these metal ions, which was closely related with the free ion concentration. This article highlights the potential use of different MOFs as biocidal material towards photosynthetic organisms and reveals important differences in the sensitivity between these organisms that should be taken into account in order to increase the biocidal spectrum of these materialsThis research was supported by the Spanish Ministry of Economy, CTM2013-45775-C2-1-R and CTM2013-45775-C2-2-

LPS promotes Th2 dependent sensitisation leading to anaphylaxis in a Pru p 3 mouse model

Pru p 3 is the major peach allergen in the Mediterranean area. It frequently elicits severe reactions, limiting its study in humans, raising the need for animal models to investigate the immunological mechanisms involved. However, no anaphylaxis model exists for Pru p 3. We aimed to develop a model of peach anaphylaxis by sensitising mice with Pru p 3 in combination with lipopolysaccharide (LPS) as an adjuvant. Four groups of mice were sensitised intranasally: untreated; treated with Pru p 3; treated with LPS; treated with Pru p 3 + LPS. After sensitisation mice were intraperitoneally challenged with Pru p 3 and in vivo and in vitro parameters were evaluated. Only mice in the Pru p 3 + LPS group showed anaphylaxis symptoms, including a decrease in temperature. Determination of in vitro parameters showed a Th2 response with an increase of Pru p 3-specific IgE and IgG1. Moreover, at the cellular level, we found increased levels of IgE and IgG1 secreting Pru p 3-specific cells and a proliferative CD4+ T-cell response. These results demonstrate that Pru p 3-specific anaphylaxis can be generated after nasal sensitisation to Pru p 3 in combination with LPS. This is a promising model for evaluating food allergy immunotherapies.Unión Europea, Ministerio de Economía y Competitividad, Instituto de Salud "Carlos III" PI12 / 02481Unión Europea, Ministerio de Economía y Competitividad, Instituto de Salud "Carlos III" PI15 / 00559Unión Europea, Ministerio de Economía y Competitividad, Instituto de Salud "Carlos III" RD 07/0064Unión Europea, Ministerio de Economía y Competitividad, Instituto de Salud "Carlos III" RD12 / 0013/0001Unión Europea, Ministerio de Economía y Competitividad, Instituto de Salud "Carlos III" RD07 / 0064/0003Unión Europea, Ministerio de Economía y Competitividad, Instituto de Salud "Carlos III" RD12 / 0013/0016Unión Europea, Ministerio de Andalucía Economía y Conocimiento CTS-7433Unión Europea, Ministerio de Andalucía Economía y Conocimiento C-0044-2012 SAS2013Unión Europea, Ministerio de Andalucía Economía y Conocimiento Ref. CD14 / 00242Unión Europea, Ministerio de Andalucía Economía y Conocimiento BIO2013- 41403-

Untangling the biological effects of cerium oxide nanoparticles: The role of surface valence states

Cerium oxide nanoparticles (nanoceria; CNPs) have been found to have both pro-oxidant and antioxidant effects on different cell systems or organisms. In order to untangle the mechanisms which underlie the biological activity of nanoceria, we have studied the effect of five different CNPs on a model relevant aquatic microorganism. Neither shape, concentration, synthesis method, surface charge (ζ-potential), nor nominal size had any influence in the observed biological activity. The main driver of toxicity was found to be the percentage of surface content of Ce3+ sites: CNP1 (58%) and CNP5 (40%) were found to be toxic whereas CNP2 (28%), CNP3 (36%) and CNP4 (26%) were found to be non-toxic. The colloidal stability and redox chemistry of the most and least toxic CNPs, CNP1 and CNP2, respectively, were modified by incubation with iron and phosphate buffers. Blocking surface Ce3+ sites of the most toxic CNP, CNP1, with phosphate treatment reverted toxicity and stimulated growth. Colloidal destabilization with Fe treatment only increased toxicity of CNP1. The results of this study are relevant in the understanding of the main drivers of biological activity of nanoceria and to define global descriptors of engineered nanoparticles (ENPs) bioactivity which may be useful in safer-by-design strategies of nanomaterialsThis research was supported by CTM2013-45775-C2-1-R and CTM2013-45775-C2-2-R grants from MINECO, the Dirección General de Universidades e Investigación de la Comunidad de Madrid, Research Network S2013/MAE-2716 and National Science Foundation for Nanotechnology Research (EECS – 0901503, CBET-1261956). Gerardo Pulido-Reyes thanks the Spanish Ministry of Education for the award of an FPU grant

Reverse Trojan-horse effect decreased wastewater toxicity in the presence of inorganic nanoparticles

We studied the toxicological interaction of 46 micropollutants from a biologically treated wastewater effluent in mixtures with silica, amine-modified silica, titanium dioxide and magnetite nanoparticles. The pollutants tracked in this work were polar pharmaceuticals belonging to different therapeutic groups, some of their metabolites and artificial sweeteners, the concentrations of which were mostly in the tens to hundreds of ng L-1 range. The results showed particularly high adsorption for furosemide, gemfibrozil and the aminopyrine metabolite 4FAA. There was preferential adsorption of the less polar compounds on the less polar nanoparticles. The total amounts of compounds adsorbed and quantified were 13.4, 4.8, 10.8 and 7.1 μg g-1 for SiO2, SiO2-NH2, TiO2 and Fe3O4, respectively. The toxicity of wastewater-nanoparticle mixtures was assessed using the bioluminescent cyanobacterium Anabaena sp. PCC 7120 CPB4337. The interactions were quantified by means of the combination index (CI)-isobologram method. The binary mixtures of wastewater with SiO2, SiO2-NH2 and TiO2 displayed antagonism for the lower affected fractions, which corresponded to the lower concentrations. For higher effects and for the Fe3O4 nanoparticles over the whole tested range, the mixtures were additive leading to synergism for the higher affected fractions. No internalization was observed. The results showed that the reduced toxicant bioavailability due to the interaction with nanoparticles is relevant for micropollutants at environmental concentrations. The amount of anthropogenic pollutants retained by metal oxide nanoparticles has significant toxicological effectsFinancial support was provided by FP7-ERA-Net Susfood, 2014/00153/001, the Spanish Ministry of Economy, CTM2013-45775-C2-1-R and CTM2013-45775-C2-2-R and the Dirección General de Universidades e Investigación de la Comunidad de Madrid, Network S2013/MAE-271

Effect of a Graduated Walking Program on the Severity of Obstructive Sleep Apnea Syndrome. A Randomized Clinical Trial

Background: Obstructive sleep apnea syndrome (OSAS) is a common disease. The objective of this research was to determine the effectiveness of a graduated walking program in reducing the apnea–hypopnea index number in patients with obstructive sleep apnea syndrome (OSAS). Methods: A randomized controlled clinical trial with a two-arm parallel in three tertiary hospitals was carried out with seventy sedentary patients with moderate to severe OSAS. Twenty-nine subjects in each arm were analyzed by protocol. The control group received usual care, while usual care and an exercise program based on progressive walks without direct supervision for 6 months were offered to the intervention group. Results: The apnea–hypopnea index decreased by six points in the intervention group, and improvements in oxygen desaturation index, total cholesterol, and Low-Density Lipoprotein of Cholesterol (LDL-c) were observed. A higher decrease in sleep apnea–hypopnea index (45 ± 20.6 vs. 34 ± 26.3/h; p = 0.002) was found in patients with severe vs. moderate OSAS, as well as in oxygen desaturation index from baseline values (43.3 vs. 34.3/h; p = 0.046). Besides, High-Density Lipoprotein of Cholesterol (HDL-c) values showed a higher increase in the intervention group (45.3 vs. 49.5 mg/dL; p = 0.009) and also, a higher decrease in LDL-c was found in this group (141.2 vs. 127.5 mg/dL; p = 0.038). Conclusion: A home physical exercise program is a useful and viable therapeutic measure for the management of OSAS

Allergen exposure boosts peripheral Th9 responses in patients with local allergic rhinitis

Key points ∙ Intranasal allergen exposure increases peripheral total Th2 and Th9 cells in patients with local allergic rhinitis (LAR). ∙ Peripheral T-cell response seems dominated by Th9 cells in patients with LAR, whereas Th2 responses prevail in patients with allergic rhinitis. ∙ Our results identify Th9 cells as potential therapeutic targets for patients with LAR.Instituto de Salud Carlos III (ISCIII) of the Spanish Ministry of Science and Competitiveness, Grant/Award Number: PI20/01715; Regional Ministry of Health of Andalucia through research projects, Grant/Award Numbers: PI-0346-2016, PI-0176-2018; Regional Ministry of Education of Andalucia through a research project, Grant/Award Number: P20-00405; Francisca Palomares holds a Senior Postdoctoral Program contract, Grant/Award Number: RH-0028-2021; Almudena Testera-Montes a “Rio Hortega” contract, Grant/Award Number: CM20/00160; Carlos Jose Aranda a “Sara Borrell” contract, Grant/Award Number: CD21/00034; Carmen Alba-Linero a “Río Hortega” contract, Grant/Award Number: CM21/00262; Ibon Eguiluz-Gracia a “Juan Rodes” contract, Grant/Award Number: JR19/00029; Cristobalina Mayorga holds a “Nicolas Monardes” contract, Grant/Award Number: RC-0004-2021; Asma, ReaccionesAdversas y Alérgicas-ARADyAL, Grant/ Award Number: RD16/0006/0001; Redes de InvestigacionCooperativaOrientadas al Resultado en Salud: Enfermedades Inflamatorias, Grant/Award Number: RD21/0002/0008 Funding for open access charge: Universidad de Málaga/CBU